The invention relates to an arrangement for changing a drilling component in a rock drilling apparatus comprising a carrier and a boom arranged manoeuvrably to it, to which boom a drilling unit is manoeuvrably arranged, the drilling unit comprising at least a rock drill, a feeding beam and feeding means, and which arrangement further comprises at least one component magazine for storing the drilling components required in drilling and a changing unit for handling the drilling components between the component magazine and the drilling unit.
Extremely heavy stress is directed to a drill bit used in rock drilling, and as a result of it, the drill bit needs occasionally to be changed due to wear and possible damage to it. For efficient rock drilling, a drill bit in good condition is required. In a known solution, the replacing apparatus of the drill bit with its magazine is arranged to the drilling unit. The solution has the drawback, however, that the weight and outer dimensions of the drilling unit necessarily increase in such a solution, whereby handling the drilling unit is difficult and visibility to the object being drilled is poor. A heavy structure requires a robust boom and heavy means for moving the drilling unit, which factors naturally increase the manufacturing costs of the equipment. Further, maintaining the equipment and defining its settings is difficult when the drill bit magazine and the changing unit are arranged tightly to the feeding beam. In addition removing used drill bits and bringing in new ones to the magazine is awkward. Further, it is not in all cases possible to store enough drill bits in the drilling unit, since the weight and outer dimensions of the magazine limit the number of drill bits. Equipment has been developed to solve the above problems, in which equipment the drill bits are already attached to the ends of the drill rods and arranged to a magazine on a carrier. The problem with these solutions is that the rod handling apparatuses require several degrees of freedom in order to be able to move the drill rod with its drill bits from the magazine to the drilling unit. The solution thus requires control of complex movements and the use of expensive and easily damaged components in demanding drilling conditions. Another problem with the solution is that because the drill bits are attached to the drill rods, handling them is awkward due to their large size and weight. In addition, the magazine takes up a lot of space.
It is an object of the present invention to provide a novel arrangement for replacing the drill bit or other drilling component of a rock drill, the invention also avoiding problems occurring in prior art.
The arrangement of the invention is characterized in that the component magazine is arranged to a carrier or boom, separate from the drilling unit, and that the arrangement comprises means for driving the drilling unit to a predefined position and location with respect to the component magazine for replacing the drilling component.
The essential idea of the invention is that the drilling unit with its rock drill and feeding equipment is driven to a predefined location and position with respect to the component magazine for replacing the drilling component. This way, the relative location of the component magazine and the drilling unit driven to a certain replacement position is exactly known. The changing unit is preferably arranged to turn with respect to the carrier or the boom, whereby it is capable of moving the drilling components being replaced between the drilling unit and the magazine. The essential idea of a preferred embodiment of the invention is that the changing unit and the component magazine are arranged to the boom, whereby the movements of the boom do not affect the relative position of the changing unit, component magazine and drilling unit driven to the replacement position. The essential idea of a second preferred embodiment of the invention is that the positioning movements of the changing unit are mechanically restricted.
The invention provides the advantage that replacing the drill bit does not require complex movements of the changing unit, whereby the changing unit can be made structurally simple and, at the same time, reliable. This makes the manufacturing and operational costs of the changing unit low. Complex and fault-sensitive sensor or control apparatuses or an exact control of movements are no longer necessarily needed. The motion speed of simple movements can be made quite high, thus clearly shortening the time needed to replace the drill bit. The solution in question provides the further advantage that when the changing unit and the component magazine are arranged to the carrier or boom, they do not add to the weight and outer dimensions of the drilling unit, thus making handling the equipment easier, allowing a better visibility to the drilling location and in addition, making it possible to design the structures and drives of the drilling unit smaller and, at the same time, less expensive. On the other hand, locating the component magazine to the boom or carrier allows the use of a larger magazine or of several magazines, thus providing a longer uninterrupted operation time of the drilling unit.